1. Field of the Invention
This invention relates to a method for joining wiring boards each having a thin resin base plate suitable for instant connection with a reduced cost, a method for manufacturing a data carrier readable by electromagnetic waves which serves as an aviation tag, a label for transportation management, a non-clerk attendant gate pass, and a device for mounting an electronic module on a body of the data carrier.
2. Description of the Related Art
According to the progress of an electronics device such as a card type electronic device, a portable telephone or an image device, recently it has become necessary that a printed circuit board, particularly a flexible printed circuit board, may be made at a reduced cost. Accordingly, a joining unified technique in flexible thin printed circuit plates 10 and 20, particularly an electrical connection between conductive patterns 12 and 22 on each wiring plate, as shown in FIGS. 12 and 13 is required to be performed at a reduced cost.
Several conventional methods have been introduced for joining printed circuit boards 10 and 20 providing conductive patterns 12 and 22 formed respectively over one surfaces of insulating base members 14 and 24.
According to a first conventional method, printed circuit boards 10 and 20 are joined each other by bonds such as epoxy bonding material, through-holes are made penetrating joining points 13 and 23 which are join predetermined portions, and insides of the through holes are electrically connected by metal conductive plating (such as a copper Cu) formed thereon, whereby multiple layer printed circuit boards are produced.
According to a second conventional method, at least one of the connection points 13 and 23 on the printed circuit boards 10 and 20 is applied by screen print with conductive bonds spread by conductive powder such as silver Ag into thermosetting property bonds, the connection points 13 and 23 are confronted each other and put together to be joined by heat-treatment with a proper pressure. Joining at a connection point 30 is performed by the above-mentioned conductive bond, but portions other than the connection point are connected by insulating bonds such as epoxy bonds, whereby the mechanical strength is increased.
According to a third method which is proposed in view of deletion of the process of the application of electrical conductive bonds and thermosetting property in the above-mentioned second method or reduction of cost by reducing the processing time, a previously formed connection sheet is inserted between connection points 13 and 23 of the printed circuit boards 10 and 20 to be heat pressure welded for connecting the connection points 13 and 23. The connection sheet is provided with a circuit formed by conductive paint and thermoplasticity bond paint thereon applied on polyester film (PET), and inserted between the connection points 13 and 23 to be heat-pressure welded, whereby the thermoplasticity bond is melted and the connection point 13 subsequently comes into contact with a conductive paint circuit and the connection point 23, so that the thermoplasticity bond is hardened by cooling the same to complete the connection process. In this method, the process of application by the conductive bond to the printed circuit boards 10 and 20 is unnecessary, and the connection time may be reduced by employing the thermoplasticity bond.
These conventional methods, however, have several disadvantages. In the first and second conventional methods, there are many processes of bonding-material application, plating, and heat treatment which need other connection member such as bonding material, plating metal, and electroconductivity bonding-material, resulting into cost increase. The connection process becomes very difficult after the electronic components 11 and 21 are mounted on the printed circuit boards 10 and 20.
The third method may ease the process after mounting the electronic parts resulting into reduction of the process time, but the manufacturing cost may not be preferably reduced because of the necessity of other member such as the connection sheet.
It is, therefore, a primary object of this invention to provide an improved method for joining wiring boards each other, which may be performed by a reduced cost and applied to the boards assembled by electronic components, and the processing time which may be reduced.
According to a first aspect of this invention, there is provided a method for joining a first wiring board covered with a conductive pattern on a surface of a thin resin basic plate to a second wiring board covered with a conductive pattern on a thin resin basic plate to ensure the electric connection therebetween, including the steps of putting the first and second wiring boards together in a confront relationship so as to adjust join predetermined portions on the conductive patterns, catching the join predetermined portions in the status by a pair of ultrasonic welding tools, and applying an ultrasonic vibration to the ultrasonic welding tools to weld the conductive metals located on the join predetermined portions.
According to this method, any separate member such as glues is not necessary for connection and processing time is extremely short, thereby reducing the joining work cost and the device cost. Moreover, the application area is limited to a peripheral of the connection points, thereby simplifying a connection process of the printed wiring boards after assembled by electronic components. The connection process is free from wetness with separate glue member, incomplete connection, thereby enabling connection between conductors of different metals such as copper (Cu) and aluminum (Al).
According to a second aspect of this invention, there is provided a method as set forth in the first aspect of this invention for joining the wiring boards, in which a plurality of projections each having an end face shape corresponding to a desired welding portion shape are disposed on at least one of opposite end faces of the pair of ultrasonic welding tools, further including the steps of partially removing a conductive metal due to plasticity flow of the metal when an ultrasonic vibration is applied by the projections, and welding plastics exposed by the removed portion.
According to this method, after metal conductors of a printed wiring board composed of insulating resins and the metal conductors are welded by ultrasonic vibrations, the conductive metal is partially removed by employing plasticity flow of metal by the ultrasonic vibrations, and the exposed plastic members are welded. Accordingly, the electrical connection between conductive patterns is executed by metal welding, and the mechanical strength of the connection is sufficiently ensured by plastic members and welding. The above-described effects of the ultrasonic may be found in the connection between metal foils.
According to a third aspect of this invention, there is provided a method for manufacturing a film-type data carrier by joining an electronic component module in which a conductive pattern is adhered on a surface of a film-type resin small piece and electronic components, providing a transmission and reception circuit, and a memory mounted thereon, to a data carrier body having a spiral conductive pattern providing an antenna adhered on a surface of a film-type resin base plate, to be unified to ensure an electrical conduction for reading electromagnetic waves, including the steps of putting the film-type resin base plate of the data carrier body and the film-type resin small piece of the electronic component module together in a face-to-face relationship to adjust join predetermined portions on the conductive patterns, catching the adjusted join predetermined portions by a pair of ultrasonic welding tools, and applying an ultrasonic vibration to the ultrasonic welding tools to weld the conductive metals located on the join predetermined portions.
According to this method, any member such as conductive glue materials is unnecessary for electrical connection between terminals, resulting into an assembly work at a reduced cost. Moreover, enlargement of connection area by ultrasonic welding may provide sufficient mechanical connection strength to fix the electronic component module. Different kinds of metals may be joined, such as an aluminum pattern on the module and a copper pattern on the data carrier body. Wide selection is also available as to the materials of the antenna coil or the mounting method of the electronic components. The joining time by ultrasonic waves is short such as two or three seconds, and supply of such a component as glue is not necessary, thereby resulting into simplification of the manufacturing apparatus.
The ultrasonic wave joining is based on a principle in which a passivity layer on a surface of metals is mechanically removed by vibrations, and an exposed new area is joined. Accordingly, electrical connection between terminals may be made without peeling an insulating etching resist used in an etching method for producing an antenna coil, resulting into reduction of a manufacturing cost caused by peeling of the etching resist, and deletion of an additional process for covering pattern surfaces with an insulating layer.
According to a fourth aspect of this invention, there is provided a method as set forth in the third aspect of this invention for manufacturing a data carrier in which a plurality of projections each having end face shape corresponding to a desired welding portion shape are disposed on at least one of opposite end faces of the ultrasonic welding tool, and welding plastics exposed by the removed portion.
This method enhances the joining strength of the electronic component module against the data carrier body is enhanced, and improves the reliability of the data carrier against rough handling applied to labels for management of material distribution or aviation tags.
According to a fifth aspect of this invention, there is provided an electronic component module mounting device for mounting an electronic component module on a data carrier body in a manufacturing process for an electromagnetic wave readable film-type data carrier, including a punch work die having a mold configuration corresponding to the electronic component module, a punch to be inserted into the punch work die, a support table disposed opposing to a punching forward direction of the die to push the data carrier body backward, and an ultrasonic horn applying ultrasonic wave vibrations to the punch, in which the electronic component module is punched out from an electronic component mounting film base by the die and the punch, the punched out electronic component module is pushed to the data carrier body in proportion to the forward movement of the punch to be welded on the data carrier body by applying ultrasonic wave vibrations to the punch by driving the ultrasonic horn. Thus, an ultrasonic wave junction technique may be introduced into a continuous manufacturing process for the data carrier.